[S390] Fix tlb flushing with idte.

The clear-by-asce operation of the idte instruction gets an asce
(address-space-control-element) as argument to specify which TLBs
need to get flushed. The current code passes a plain pointer to
the start of the pgd without the additional bits which would make
the pointer an asce. The current machines don't mind the difference
but a future model might want to use the designation type control
bits in the asce as a filter for the TLBs to flush.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index a87b197..79dccd2 100644 (file)
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -157,7 +157,7 @@ startup_continue:
        .long   0xb2b10000              # store facility list
        tm      0xc8,0x08               # check bit for clearing-by-ASCE
        bno     0f-.LPG1(%r13)
-       lhi     %r1,2094
+       lhi     %r1,2048
        lhi     %r2,0
        .long   0xb98e2001
        oi      7(%r12),0x80            # set IDTE flag

diff --git a/include/asm-s390/mmu_context.h b/include/asm-s390/mmu_context.h
index 05b8421..a77d4ba 100644 (file)
--- a/include/asm-s390/mmu_context.h
+++ b/include/asm-s390/mmu_context.h
@@ -12,10 +12,15 @@
 #include <asm/pgalloc.h>
 #include <asm-generic/mm_hooks.h>
 
-/*
- * get a new mmu context.. S390 don't know about contexts.
- */
-#define init_new_context(tsk,mm)        0
+static inline int init_new_context(struct task_struct *tsk,
+                                  struct mm_struct *mm)
+{
+       mm->context = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
+#ifdef CONFIG_64BIT
+       mm->context |= _ASCE_TYPE_REGION3;
+#endif
+       return 0;
+}
 
 #define destroy_context(mm)             do { } while (0)
 
@@ -27,19 +32,11 @@
 
 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
 {
-       pgd_t *pgd = mm->pgd;
-       unsigned long asce_bits;
-
-       /* Calculate asce bits from the first pgd table entry. */
-       asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
-#ifdef CONFIG_64BIT
-       asce_bits |= _ASCE_TYPE_REGION3;
-#endif
-       S390_lowcore.user_asce = asce_bits | __pa(pgd);
+       S390_lowcore.user_asce = mm->context | __pa(mm->pgd);
        if (switch_amode) {
                /* Load primary space page table origin. */
-               pgd_t *shadow_pgd = get_shadow_table(pgd) ? : pgd;
-               S390_lowcore.user_exec_asce = asce_bits | __pa(shadow_pgd);
+               pgd_t *shadow_pgd = get_shadow_table(mm->pgd) ? : mm->pgd;
+               S390_lowcore.user_exec_asce = mm->context | __pa(shadow_pgd);
                asm volatile(LCTL_OPCODE" 1,1,%0\n"
                             : : "m" (S390_lowcore.user_exec_asce) );
        } else

diff --git a/include/asm-s390/tlbflush.h b/include/asm-s390/tlbflush.h
index a69bd24..a5e8765 100644 (file)
--- a/include/asm-s390/tlbflush.h
+++ b/include/asm-s390/tlbflush.h
@@ -42,11 +42,11 @@ static inline void __tlb_flush_global(void)
 /*
  * Flush all tlb entries of a page table on all cpus.
  */
-static inline void __tlb_flush_idte(pgd_t *pgd)
+static inline void __tlb_flush_idte(unsigned long asce)
 {
        asm volatile(
                "       .insn   rrf,0xb98e0000,0,%0,%1,0"
-               : : "a" (2048), "a" (__pa(pgd) & PAGE_MASK) : "cc" );
+               : : "a" (2048), "a" (asce) : "cc" );
 }
 
 static inline void __tlb_flush_mm(struct mm_struct * mm)
@@ -61,11 +61,11 @@ static inline void __tlb_flush_mm(struct mm_struct * mm)
         * only ran on the local cpu.
         */
        if (MACHINE_HAS_IDTE) {
-               pgd_t *shadow_pgd = get_shadow_table(mm->pgd);
+               pgd_t *shadow = get_shadow_table(mm->pgd);
 
-               if (shadow_pgd)
-                       __tlb_flush_idte(shadow_pgd);
-               __tlb_flush_idte(mm->pgd);
+               if (shadow)
+                       __tlb_flush_idte((unsigned long) shadow | mm->context);
+               __tlb_flush_idte((unsigned long) mm->pgd | mm->context);
                return;
        }
        preempt_disable();